ARCO Mercury 1970-2006 Outboard Ignition Coil

The ARCO replacement ignition coil is used across a long range of Mercury outboards built from the 1970s through the mid-2000s. The supplier fitment spans two-, three-, four-, and six-cylinder engines, with horsepower ranges extending from small portable-size applications through large V6 outboards. Because the same coil design appears across many years and model families, cross-referencing the original part is an important part of selection. The component is intended as a direct marine ignition replacement without modification to the original system.

Mercury references include 339-832757A4, 7370A8, 7370A2, 4995A2, 4774A1, 7370A6, 7370A19, 7370A16, 832757A3, 7370A23, 7370A17, F718475, 832757B4, and 7370B13. Sierra 18-5186 is also listed as an interchange number. That extensive cross-reference history reflects the coil’s use across multiple generations of Mercury ignition systems. Comparing the existing coil number and connector arrangement is more reliable than selecting by horsepower alone.

While replacing the coil, inspect the high-tension lead, primary terminals, grounds, and nearby harness for corrosion or heat damage. Poor connections can create misfire or no-spark symptoms that remain after a new coil is installed. ARCO lists 12-month parts-and-labor warranty protection for this component. Confirm ignition quality under normal engine load after the repair is complete.

• Broad application range across Mercury two-, three-, four-, and six-cylinder outboards
• Extensive Mercury OEM cross-reference coverage
• Also cross-references Sierra 18-5186
• Direct replacement for the specified original ignition systems

For more Mercury outboard ignition coils and related control-system parts, Browse more Engine Controls & Ignition for related replacement and service components.